Liquid chromatography (LC) is a technique for performing an analytical separation or a preparative separation of a liquid-phase material of interest (e.g., a mixture of different chemical compounds) into constituent components. During the course of a chromatographic separation, the material of interest is transported in a mobile phase (or solvent). The mobile phase is forced through a stationary phase that is immiscible relative to the mobile phase. Typically, the stationary phase is provided in the form of a volume of particles (a column packing bed) supported in a column through which the material to be separated and the mobile phase flow. The column packing bed is typically retained at each end of the column by a frit or filter that allows the mobile phase and the material to be separated to flow through while preventing the packing material from escaping the column. In the column, the respective compositions of the mobile phase and stationary phase are selected to cause differing components of the material of interest to become distributed between the mobile phase and stationary phase to varying degrees dependent on the respective chemistries of the material's components. Components that are strongly retained by the stationary phase travel slowly with the mobile phase, while components that are weakly retained by the stationary phase travel more rapidly. As a result, components of differing compositions become separated from each other as the mobile phase flows through the column.
In analytical separation, the components are separated to facilitate their analysis by known detecting techniques. Analytical separation typically entails the use of a small amount of material and small inside-diameter columns (e.g, less than 1 inch). In preparative separation, the components are separated to purify or isolate one or more chemical components from the starting material, which may be done for a further use such as reaction, synthesis, etc. Preparative separation is typically performed on a much larger scale to purify a large quantity of material, and hence typically utilizes large inside-diameter columns (e.g., 1-24 inches).
The packing and handling of large columns have conventionally required the use of large, heavy equipment. Large columns are typically packed by a flow packing technique, which entails suspending the particulate packing material in a suitable solvent to form a slurry, forcing the slurry into the column to retain the packing material while allowing the solvent to pass through the column, and then rapidly compressing the packing material by axial compression to form a uniform, tightly-packed bed at a desired final pressure. Axial compression is typically accomplished by driving a piston head through the column and into contact with the packing material. Axial compression and handling of columns is typically done pneumatically, which may not be sufficiently robust for larger-scale columns. Moreover, axial compression typically requires a column to be loaded into a column packing station. The packing station is often stationary or at least too heavy or bulky to be transported easily, and the column is often too large or heavy to be handled easily. Consequently, the packing station is often required to be located directly at the site of operation of the column, i.e., the location where the column is utilized to perform separation. Thus, there is a risk that fluids or other components of the packing station may contaminate the column, and the packing station may not be available to pack other columns while the packed column is being utilized in a separation process. Moreover, the typical packing station is compatible for use with only one or a few different column sizes, and is limited to a narrow range of packing pressures.
In view of the foregoing, there is a need for providing chromatographic column hardware configured for easier and more robust handling and packing of columns of differing sizes, including large-scale columns, and over a wide range of selectable packing pressures and packing material compositions. There is also a need for improving the mobility of columns to enable a packed column to be easily transported to a site of operation located remotely from the packing station, so as to isolate the separation process from the packing/unpacking process and prevent decompression of the packed column. There is also a need for reducing the bulk and weight of the apparatus utilized for handling and transporting a packed column.